Utilization of optically active secondary phosphine–boranes: synthesis of P-chiral diphosphines and their enantioinduction ability in rhodium-catalyzed asymmetric hydrogenation

摘要: Abstract Both enantiomers of tert-butylmethylphosphine–borane have been used for the synthesis P-chiral diphosphines and/or their borane complexes. The enantiopure complex 1,2-bis(tert-butylmethylphosphino)ethane (t-Bu-BisP∗) was prepared in high yield from secondary phosphine–borane and 1,2-dichloroethane. A mono-chelated Rh-complex t-Bu-MiniPHOS its catalytic activity examined asymmetric hydrogenation some representative functionalized alkenes. Synthesis three new phosphine ligands with quinoline or quinoxaline backbone is also described together enantioinduction ability.